JP5824631B2 - Non-contact charging module and charger and electronic device using the same - Google Patents

Description

  The present invention relates to a non-contact charging module having a planar coil portion and a magnetic sheet, a charger using the same, and an electronic device.

  In recent years, many devices that can charge the main device in a non-contact manner with a charger have been used. In this method, a power transmission coil is arranged on the charger side, a power reception coil is arranged on the main device side, and electromagnetic induction is generated between the two coils to transmit power from the charger side to the main device side. It has also been proposed to apply a mobile terminal device or the like as the main device.

  The main device such as the portable terminal device and the charger are required to be thin and small. In order to meet this demand, it is conceivable to provide a planar coil portion wound in a circle as a power transmission coil or a power reception coil and a magnetic sheet as in (Patent Document 1).

  As an example, a standard proposal has been made to provide a circular magnet at the center of a power transmission coil for positioning the power transmission coil and the power reception coil.

JP 2006-42519 A

  However, in the prior art described in Patent Document 1, when a magnet is attached on the center of the coil, the magnetic characteristics of the magnetic sheet are weakened by the magnetic field generated from the magnet. Therefore, in order to avoid the influence of the magnetic field of the magnet, the diameter of the planar coil has to be increased, and as a result, the contactless charging module cannot be reduced in size.

  Therefore, in view of the above problems, the present invention provides a non-contact charging module capable of preventing the power transmission efficiency of the non-contact charging module from being deteriorated and thereby reducing the size of the non-contact charging module, and a charger using the same. And to provide electronic equipment.

  In order to solve the above-described problem, the present invention provides a non-contact charging module that performs power transmission by electromagnetic induction with the other non-contact charging module, and the other non-contact charging module is aligned with the other non-contact charging module. There are cases where alignment is performed using a circular magnet provided in the hollow portion of the planar coil portion of the contact charging module, and cases where alignment is performed without using the circular magnet, and for the alignment itself. In a non-contact charging module that does not have a magnet, a planar coil part in which a conducting wire is wound with a substantially rectangular hollow part inside, and a substantially rectangular magnetic sheet on which the coil surface of the planar coil part is placed; The non-contact charging module is characterized in that the magnetic sheet is larger than the planar coil portion.

As described above, according to the present invention, since the coil coil inner area of the planar coil can be increased while the installation area of the planar coil portion is the same as the installation area when the conventional circular coil is used, alignment is performed. For this reason, even if there is a magnet at the center of the coil, it is possible to prevent the power transmission efficiency of the contactless charging module from being lowered, thereby making the contactless charging module thinner and smaller.

Assembly drawing of the non-contact charging module in the first embodiment of the present invention The conceptual diagram of the magnetic sheet of the non-contact charge module in the 1st Embodiment of this invention Arrangement of coils of contactless charging module in the first embodiment of the present invention The figure which shows the relationship between the coil inner dimension of the non-contact charge module in the 1st Embodiment of this invention, and the L value reduction rate of a coil. The figure which displays the magnitude | size of the magnetic field of the non-contact charge module in the 1st Embodiment of this invention The figure which shows the relationship between the thickness of the ferrite sheet of the non-contact charge module in the 1st Embodiment of this invention, and the L value of a coil The schematic diagram which shows the positional relationship of the magnet with which the non-contact charge module and the other non-contact charge module which performs electric power transmission in the 2nd Embodiment of this invention were equipped.

  The invention according to claim 1 is a non-contact charging module that performs electric power transmission with the other non-contact charging module by electromagnetic induction, and the other non-contact charging is performed at the time of alignment with the other non-contact charging module. There are cases where alignment is performed using a circular magnet provided in the hollow portion of the planar coil portion of the module, and cases where alignment is performed without using the circular magnet. In a non-contact charging module that does not have, a planar coil portion around which a conducting wire is wound with a substantially rectangular hollow portion inside, and a substantially rectangular magnetic sheet on which the coil surface of the planar coil portion is placed, The contactless charging module is characterized in that the magnetic sheet is larger than the planar coil portion.

  According to the first aspect of the present invention, even if there is a magnet at the center of the coil for alignment, it is possible to prevent the power transmission efficiency of the non-contact charging module from deteriorating. And the thickness reduction and size reduction of a non-contact charge module can be achieved. The magnetic sheet provided can prevent magnetic flux leakage from the flat coil portion to the back side of the magnetic sheet and can be useful for attraction with a magnet used for alignment.

  The invention according to claim 2 is a charger comprising the non-contact charging module according to claim 1 as a charging non-contact charging module.

  According to the invention of claim 2 in the present invention, by avoiding the influence of the magnetic field of the alignment magnet by making the planar coil used by the contactless charging module rectangular, by improving the power transmission efficiency of the contactless charging module, The charger can be thinned.

  According to a third aspect of the present invention, there is provided an electronic apparatus comprising the non-contact charging module according to the first aspect as a power-receiving non-contact charging module.

  According to the invention of claim 3 in the present invention, by avoiding the influence of the magnetic field of the alignment magnet by making the planar coil used by the non-contact charging module rectangular, by improving the power transmission efficiency of the non-contact charging module, Electronic devices can be thinned.

(First embodiment)
Hereinafter, a first embodiment of the present invention will be described with reference to the drawings.

  FIG. 1 is an assembly diagram of a contactless charging module according to the first embodiment of the present invention, and FIG. 2 is a conceptual diagram of a magnetic sheet of the contactless charging module according to the first embodiment of the present invention. The non-contact charging module 1 of the present embodiment is opposed to the planar coil portion 2 in which one circular conducting wire is wound in a substantially rectangular shape on a plane and the surface of the coil 21 of the planar coil portion 2. The plurality of conductive wires are connected to each other at both ends thereof.

  As shown in FIG. 1, the planar coil unit 2 includes a coil 21 in which a conductor is wound in a substantially rectangular shape on a plane, and terminals 22 and 23 provided at both ends of the coil 21. A surface formed by the coil 21 is referred to as a coil surface (details of the coil shape will be described later).

  In the present embodiment, the coil 21 is formed by winding one conductive wire in a substantially rectangular shape on a plane, but two or more conductive wires are wound in a substantially rectangular shape in a planar shape, May be sandwiched between the other conductors.

  Moreover, in this Embodiment, although cross-sectional area is made into the conducting wire of circular shape, conducting wire of square shape etc. may be sufficient. However, in the case of a circular conductor compared with a rectangular conductor, a gap is formed between adjacent conductors, so that the stray capacitance between the conductors is reduced, and the AC resistance of the coil 21 is reduced. Can do.

  In addition, the coil 21 is wound in one step rather than being wound in two steps in the thickness direction, so that the alternating current resistance of the coil 21 is lowered and the transmission efficiency can be increased. This is because when a conducting wire is wound in two stages, stray capacitance is generated between the upper conducting wire and the lower conducting wire. Therefore, it is better to wind as many portions as possible in one stage rather than winding the entire coil 21 in two stages. Furthermore, the non-contact charging module 1 can be thinned by winding in one stage. In addition, the loss in the coil 21 is prevented because the alternating current resistance of the coil 21 is low, and the power transmission efficiency of the non-contact charging module 1 depending on the L value can be increased by improving the L value. That is, as the L value of the coil 21 increases, the power transmission efficiency of the coil 21 of the non-contact charging module 1 increases.

  In the present embodiment, the inner width of the coil 21 shown in FIG. 1 is 10 to 20 mm, and the outer width of the outer side is about 30 mm. As the inner width is smaller, the number of turns of the coil 21 can be increased in the contactless charging module 1 of the same size, and the L value can be improved.

  In addition, although the terminals 22 and 23 may be close to each other or may be arranged apart from each other, the non-contact charging module 1 is easier to mount if they are arranged apart.

  The magnetic sheet 3 is provided in order to reduce the generation of a demagnetizing field caused by the eddy current flowing in the metal around the coil 21 due to the magnetic flux generated in the coil 21. Thereby, while improving the power transmission efficiency of the non-contact charge using an electromagnetic induction effect | action, it increases the magnetic flux which generate | occur | produces in the plane coil part 2, and prevents the magnetic flux leak from the plane coil part 2 to the magnetic sheet 3 back side. .

As shown in FIG. 2, the magnetic sheet 3 includes a flat portion 31, a central convex portion 32, and a linear concave portion. In the present embodiment, a Ni—Zn ferrite sheet, a Mn—Zn ferrite sheet, a Mg—Zn ferrite sheet, or the like can be used as the magnetic sheet 3. The ferrite sheet can reduce the AC resistance of the coil 21 as compared with the amorphous metal magnetic sheet. In addition, the center convex part 32 is not necessarily required. The magnetic sheet 3 may have a saturation magnetic flux density of 350 mT or more and a thickness of 300 μm or more.

  In the present embodiment, the magnetic sheet 3 has a rectangular shape of about 33 mm × 33 mm. The thicknesses of the flat portion 31 and the convex portion 32 are set so that d1 shown in FIG. 2 is 0.2 mm and d2 is 0.6 mm. As the magnetic sheet 3 is thicker, the inductance (L value) of the coil 21 is increased, and the power transmission efficiency is improved as the non-contact charging module. Therefore, the higher the height d1 of the convex portion 32 is, the larger the non-contact charging module 1 is. Improve transmission efficiency. However, since the thickness of the non-contact charging module 1 is increased by the height d1 of the convex portion 32 that is larger than the diameter of the conductor, the diameter of the conductor constituting the coil 21 is made substantially the same.

  Moreover, the diameter of the convex part 32 is substantially the same as the inner width of the coil 21 (see FIG. 1). That is, the center of the coil 21 and the center of the convex part 32 substantially coincide, and the coil 21 is wound around the convex part 32. Further, the depth d3 of the concave portion 33 of the linear portion extending to the end of the magnetic sheet 3 is also substantially the same as the diameter of the conducting wire constituting the coil 21, and the concave portion 33 is formed only with a minimum depth. This is because the magnetic sheet 3 becomes thinner as the concave portion 33 becomes deeper, so that the transmission efficiency of the non-contact charging module 1 is lowered.

  The width of the recess 33 is about 0.4 mm to 1 mm (the diameter of the conducting wire + about 0.1 mm). The recess 33 extends substantially perpendicular to one side of the magnetic sheet 3. By forming the recess 33 in this way, the terminals 22 and 23 can be formed without bending the conducting wire. In this case, the length of the concave portion 33 is about 15 mm to 20 mm, and it is only necessary to have a length necessary for drawing out the conducting wire. Moreover, you may make the recessed part 33 into another arrangement | positioning. That is, it is desirable that the coil 21 has a one-stage structure as much as possible. In this case, all the turns of the coil 21 have a one-stage structure, or a part has a one-stage structure and the other part has a two-stage structure. Conceivable. Accordingly, one of the terminals 22 and 23 can be pulled out from the outer periphery of the coil 21, but the other must be pulled out from the inside. Accordingly, the portion around which the coil 21 is wound and the portion from the end of winding of the coil 21 to the terminal 22 or 23 always overlap in the thickness direction. Therefore, the concave portion 33 may be provided in the overlapping portion.

  Further, the recess 33 may be a slit. That is, if it is the recessed part 33, since a through-hole and a slit are not provided in the magnetic sheet 3, it can prevent that a magnetic flux leaks and can improve the electric power transmission efficiency of the non-contact charge module 1. FIG. On the other hand, in the case of the slit, the magnetic sheet 3 can be easily formed. When it is the recessed part 33, it is not limited to the recessed part 33 whose cross-sectional shape becomes a square shape, You may be circular arc shape or rounded.

  The magnetic sheet 3 has a rectangular shape that is easy to use, and the sheet can be easily handled, and a large installation area that can be used for preventing magnetic flux leakage from the planar coil portion 2 can be taken. That is, it is possible to cover up to four gaps to be installed with the sheet, and to widen the range of preventing magnetic flux leakage from the planar coil portion 2.

  Furthermore, since the concave portion 33 or the slit made in the magnetic sheet 3 extends substantially perpendicular to one side of the magnetic sheet 3, the length or area of the concave portion or the slit can be minimized, and the amount of leakage of the magnetic flux The power transmission efficiency of the non-contact charging module 1 can be improved.

  In addition, since d1, d2, d3, etc. mentioned above depend on the diameter of conducting wire, they are not limited to said value. Moreover, d1 and d3 do not necessarily need to be the same.

Next, the shape of the coil 21 will be described in detail. FIG. 3 is a layout diagram of coils of the contactless charging module according to the first embodiment of the present invention, and FIG. 4 is an inner dimension of the coil and L of the coil of the contactless charging module according to the first embodiment of the present invention. FIG. 5 is a diagram showing the relationship with the value reduction rate, FIG. 5 is a diagram showing the magnitude of the magnetic field of the non-contact charging module in the first embodiment of the present invention, and FIG. 6 is the first embodiment of the present invention. It is a figure which shows the relationship between the thickness of the ferrite sheet of the non-contact charge module in a form, and the L value of a coil.

  FIG. 3 shows the arrangement of the planar coil portions. (A) is the rectangular planar coil part 2a in the Example of this invention, (B) is the conventional circular planar coil part 2b. Both are placed on the magnetic sheet 3 with the center thereof aligned with the center of the alignment magnet 4. Here, the alignment magnet 4 outside the non-contact charging module 1 is temporarily described so that the positional relationship with the planar coil portion can be understood.

  The alignment magnet 4 is circular with a diameter m, and the magnetic sheet 3 is a square with one side a. The magnetic sheet 3 does not have to be rectangular and square, but a square is preferable in order to reduce the size while ensuring the performance of the contactless charging module 1.

  The positioning magnet 4 has been proposed as a standard for using the non-contact charging module 1 and is used to ensure power transmission of the non-contact charging module 1 and to center the transmitting and receiving coils.

  In the present embodiment, as shown in FIG. 5, the alignment magnet 4 is attached to the electronic device on the power transmission side, and the non-contact charging module 1 is attached to the power reception side. However, the present invention is not limited to this. Instead, the alignment magnet 4 may be on the power receiving side or both. Similarly, the non-contact charging module 1 may be on the power receiving side or both.

  When the rectangular planar coil portion 2a or the circular planar coil portion 2b having the same number of windings is installed on the magnetic sheet 3, both are accommodated in the magnetic sheet 3 having the same area. That is, as shown in FIGS. 3A and 3B, a rectangular planar coil portion 2a or a circular planar coil portion 2b having the same number of windings is rectangular on a magnetic sheet 3 having a length of one side a. The shortest distance between the opposing inner sides of the planar coil portion 2a and the inner diameter of the circular planar coil portion 2b can be the same length y.

  On the other hand, the diagonal length inside the rectangular planar coil portion 2a is x longer than the shortest distance y between the opposing inner sides of the rectangular planar coil portion 2a having the same length as the inner diameter y of the circular planar coil portion 2b. That is, the rectangular planar coil portion 2a has a larger area in which the gap between the alignment magnet 4 and the planar coil portion 2 can be made larger than that of the circular planar coil portion 2b. That is, the relationship is x> y and x> m.

  FIG. 4 shows a case where the alignment magnet 4 is not present when the diagonal dimension inside the rectangular planar coil portion 2a and the inner diameter dimension of the circular planar coil portion 2b are varied (the size of the magnetic sheet 3 is also changed accordingly). The L value decreasing rate of the planar coil portion 2 when the alignment magnet 4 is present is shown. That is, the smaller the L value reduction rate, the smaller the influence of the alignment magnet.

  As shown in FIG. 4, the larger the inner dimension of the coil, the smaller the L value reduction rate of the planar coil portion 2. This is because the influence of the alignment magnet 4 is reduced because an area in which an extra space can be taken between the alignment magnet 4 and the inside of the planar coil portion 2 is increased. On the other hand, when the diagonal dimension inside the rectangular planar coil portion 2a and the inner diameter dimension of the circular planar coil portion 2b are the same value, the L value reduction rate of the planar coil portion 2 is also the same value.

That is, when the diagonal dimension x inside the rectangular planar coil part 2a and the inner diameter dimension y of the circular planar coil part 2b are larger than the diameter m of the alignment magnet 4 (x = y> m), the inner side of the planar coil part 2 And a gap between the outer periphery of the alignment magnet 4. However, in this case, the planar area of the planar coil 2 is smaller in the rectangular planar coil portion 2a than in the planar planar coil portion 2b. Therefore, the diagonal dimension inside the rectangular planar coil portion 2a can be increased so as to match the size of the magnetic sheet 3. By doing so, when the planar coil portion 2 is installed in the magnetic sheet 3, the rectangular planar coil portion 2a is aligned with the inner side of the planar coil portion 2 and the outside of the alignment magnet 4 compared to the circular planar coil portion 2b. A gap can be formed between the periphery and the influence of the positioning magnet 4 can be reduced. In the present embodiment, the diagonal dimension (x) of the rectangular planar coil portion 2a is set to approximately 23 mm and the diameter (m) of the alignment magnet 4 is set to 15 mmΦ so as to satisfy the above-described relationship.

  Next, the magnitude | size of the magnetic field which generate | occur | produces in the rectangular planar coil part 2a is demonstrated using FIG. 5B is a cross-sectional view taken along the line AA ′ of FIG. 5A, and FIG. 5C is a cross-sectional view taken along the line BB ′ of FIG. 5A. In FIG. 5B, the end of the alignment magnet 4 and the inner end of the rectangular planar coil portion 2 a are close to each other, and are generated in the rectangular planar coil portion 2 a due to the influence of the magnetic field of the alignment magnet 4. The magnetic field becomes smaller. On the other hand, in FIG. 5C, the end portion of the alignment magnet 4 and the inner end of the rectangular planar coil portion 2a are separated from each other, making it less susceptible to the magnetic field of the alignment magnet 4 and the rectangular planar coil portion. The magnetic field generated at 2a is increased.

  In short, in the circular planar coil portion 2b (see FIG. 3B) described above, the condition of FIG. 5B is satisfied everywhere on the coil circumference, and the magnetic field generated in the circular planar coil portion 2b is small, that is, electromagnetic The L value of the circular planar coil portion 2b that affects the mutual inductance of the induction becomes small, and the power transmission efficiency of the non-contact charging module is low. On the other hand, since the rectangular planar coil portion 2a (see FIG. 3A) described above is integrated from the condition of FIG. 5B to the condition of FIG. 5C on the circumference of the coil, the rectangular planar coil portion. The magnetic field generated in 2a is large, that is, the L value of the rectangular planar coil portion 2a that affects the mutual inductance of electromagnetic induction is larger than the L value of the circular planar coil portion 2b, and thus the power transmission efficiency of the contactless charging module is This is a significant improvement over the circular planar coil portion 2b.

  Next, by changing the ferrite thickness of the magnetic sheet 3 between the rectangular planar coil portion 2a (see FIG. 3A) and the circular planar coil portion 2b (see FIG. 3B), the L value of the planar coil portion 2 is set. The measurement results will be described. FIG. 6 shows the result of measuring the L value of the planar coil portion 2 by changing the ferrite thickness of the magnetic sheet 3. Here, the L value is the inductance value of the planar coil portion 2, and the larger the value, the higher the efficiency of power transmission of the non-contact charging module.

  In order to satisfy the power transmission performance of the contactless charging module, the L value of the coil 21 needs to be 6 to 8 μH. However, when the alignment magnet 4 is present, the magnetic field of the magnetic sheet 3 is affected by the alignment magnet 4. The effect of increasing strength is reduced.

  According to FIG. 6, when the alignment magnet 4 is present, the ferrite thickness of the magnetic sheet 3 needs to be 500 μm in order for the circular planar coil portion 2 b to generate 6 to 8 μH. In comparison, the L value of the rectangular planar coil portion 2a having the same ferrite thickness is 12 μH (arrow A).

  Under the condition that the ferrite thickness and area of the magnetic sheet 3 are the same, the L value of the rectangular planar coil portion 2a is larger than that of the circular planar coil portion 2b. Therefore, the magnetic field generated in the rectangular planar coil portion 2a is large, and the power transmission efficiency of the non-contact charging module is increased.

  In the case where the L value of the rectangular planar coil portion 2a and the circular planar coil portion 2b are to be made the same, the rectangular planar coil portion 2a can set the ferrite thickness of the magnetic sheet 3 to be thinner. That is, in order to set the target value of L value to 6-8 μH, the ferrite thickness of the magnetic sheet 3 of the rectangular planar coil portion 2a can be 300 μm (arrow B), and the thickness of the ferrite can be reduced. it can. Therefore, the thickness of the non-contact charging module 1 can be reduced and it is easy to reduce the size.

  In this way, the planar coil used by the non-contact charging module is made rectangular to avoid the influence of the magnetic field of the alignment magnet, and the power transmission efficiency of the non-contact charging module is improved, thereby reducing the size of the non-contact power receiving module. can do.

  Note that the coil 21 is not limited to being wound in a rectangular shape, and may be wound in a rectangular shape or a polygonal shape having an R at a corner. That is, the shape of the coil 21 may be any shape as long as the entirety is on the magnetic sheet 3 and the inner edge of the coil 21 has many portions away from the outer edge of the alignment magnet 4. Among them, the rectangular shape can obtain the above-described effects and can easily form a rectangular coil.

  In the present embodiment, the winding of the coil 21 of the rectangular planar coil portion 2a is described as a square, but is not limited to this and may be a rectangle. That is, if at least a part of the four inner sides of the coil 21 is located outside the outer periphery of the alignment magnet 4, the above-described effect can be obtained.

  The alignment magnet 4 is not necessarily installed in both the power transmission and power reception non-contact charging modules, and may be installed on one side. In the present embodiment, the alignment magnet 4 is not installed in the non-contact charging module 1 but described in the case where it is installed in the non-contact charging module 1 that is the counterpart. Can be explained in the same way even if is on your side.

  Next, the non-contact electronic device (not shown) provided with the non-contact charge module 1 of this invention is demonstrated. The non-contact electronic device includes a charger (power transmission module) including a power transmission coil and a magnetic sheet, and a main device (power reception module) including a power reception coil and a magnetic sheet. It has become an electronic device. The circuit on the charger side includes a rectifying / smoothing circuit unit, a voltage conversion circuit unit, an oscillation circuit unit, a display circuit unit, a control circuit unit, and the power transmission coil. The circuit on the main device side includes the power receiving coil, a rectifier circuit unit, a control circuit unit, and a load L mainly composed of a secondary battery.

  Since the contactless electronic device of the present embodiment includes the contactless charging module described above, the planar coil used by the contactless charging module is rectangular to avoid the influence of the magnetic field of the alignment magnet, and contactless charging. The contactless electronic device can be reduced in size and thickness by improving the power transmission efficiency of the module.

  Next, a non-contact power transmission system (not shown) provided with the non-contact charging module 1 of the present invention will be described.

The non-contact power transmission system transmits power to a charger (power transmission module) including a power transmission coil and a magnetic sheet, a main device (power reception module) including a power reception coil and a magnetic sheet, and the main device side. The main unit is an electronic device such as a mobile phone. The charger side includes a rectifying and smoothing circuit unit, a voltage conversion circuit unit, an oscillation circuit unit, a display circuit unit, a control circuit unit, and the power transmission coil. The main device side is composed of the power receiving coil, a rectifier circuit section, and a load L mainly composed of a secondary battery. And it is comprised by the control part which performs the electric power transmission optimally between the charger side and the main body equipment side. The control unit includes a detector that checks a charging state on the main device side, and a control circuit unit that controls the amount of charge to the main device side according to the output of the detector.

  The control unit may be integrated with the charger side, or may be connected with a signal cable or the like separately from the charger side.

  The power transmission system from the charger to the main device uses the non-contact charging module 1 of the present invention, and the power transmission coil of the charger on the primary side and the power reception coil of the main device on the secondary side. It is performed in a non-contact manner using the electromagnetic induction action.

  Since the contactless power transmission system of the present embodiment includes the contactless charging module described above, the planar coil used by the contactless charging module is made rectangular to avoid the influence of the magnetic field of the alignment magnet and contactlessly. By improving the power transmission efficiency of the charging module to sufficiently secure the cross-sectional area of the planar coil portion and improving the power transmission efficiency, the contactless electronic device can be reduced in size and thickness.

  In the contactless electronic device and the contactless power transmission system according to the present embodiment, the contactless charging module 1 of the present invention is used for both the charging module and the power receiving module. It may be used for either the module or the power receiving module.

(Second Embodiment)
Hereinafter, a second embodiment of the present invention will be described with reference to FIG. Here, members having the same configuration and function as those of the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

  The difference between the present embodiment and the first embodiment is the relationship between the inner dimension of the rectangular planar coil portion 2 a and the diameter of the alignment magnet 4. Hereinafter, this different point will be described in detail.

  FIG. 7 is a schematic diagram showing the positional relationship between alignment magnets provided in the non-contact charging module and the other non-contact charging module that performs power transmission in the second embodiment of the present invention. The contact charging module includes an alignment magnet 4 used for alignment of the primary side non-contact charging module and the secondary side non-contact charging module. FIG. 7A shows the case where the secondary coil is a rectangular coil, and FIG. 7B shows the case where the secondary coil is a circular coil.

  At this time, regarding the relationship between the alignment magnet and the non-contact charging module, the alignment magnet provided in the primary non-contact charging module (power transmission module) and the secondary non-contact charging module (power receiving module) And the relationship between the secondary non-contact charging module and the alignment magnet provided in the primary non-contact charging module.

  The primary-side non-contact charging module (power transmission module) and the secondary-side non-contact charging module (power-receiving module) have been described in the non-contact power transmission system in the first embodiment described above. Is.

Therefore, the relationship between the secondary-side non-contact charging module and the alignment magnet provided in the primary-side non-contact charging module will be described as an example, but the primary-side non-contact charging module and the secondary-side non-contact charging module will be described. This also applies to the relationship with the alignment magnet provided.
In other words, the influence of the alignment magnet provided in the other non-contact charging module that is the partner of power transmission is suppressed, and even if the other non-contact charging module is provided with the alignment magnet, it is not provided. Even if it exists, it can apply about the non-contact charge module in which alignment and electric power transmission are possible. The magnet is circular in the present embodiment, but may have any shape such as a polygon, a rectangle, or a square.

  The center of the secondary rectangular planar coil portion 2a shown in FIG. 7A and the secondary circular planar coil portion 2b shown in FIG. 7B is provided in the primary non-contact charging module. The alignment is performed so as to be aligned with the center of the alignment magnet 4. Even if the primary side non-contact charging module does not provide the alignment magnet 4, the secondary side non-contact charging module may include the alignment magnet 4.

  The alignment magnet 4 has been proposed as a standard for using the non-contact charging module, and ensures power transmission between the non-contact charging module between the primary side and the secondary side, and the primary side and the secondary side. Are used to center the planar coil 21 (see FIG. 1). The alignment magnet 4 has a circular shape with a diameter m, and is specified by a standard (WPC) to be circular, the diameter m being 15.5 mm or less, and the like.

  The magnetic sheet 3 is square. The magnetic sheet 3 may be a polygon other than a square, a rectangle, or a corner with a curve (corner), but a square is preferable for miniaturization while ensuring the performance of the non-contact charging module.

  When the rectangular secondary side planar coil part 2a or circular secondary side planar coil part 2b having the same number of windings is installed on the magnetic sheet 3 of the same size, both are in the magnetic sheet 3 of the same area. Will fit in. In such a case, the rectangular secondary planar coil portion 2a has a square coil shape.

  That is, as shown in FIGS. 7A and 7B, a rectangular secondary planar coil portion 2a or a circular secondary planar coil portion 2b having the same number of windings is installed on a square magnetic sheet 3. In this case, the shortest distance y1 between the opposing inner sides of the rectangular secondary side planar coil portion 2a and the inner diameter y2 of the circular planar coil portion 2b can be made the same length.

  On the other hand, the diagonal length x inside the planar coil portion 2a on the secondary side of the rectangle is longer than the shortest distance y1 between the opposing inner sides of the planar coil portion 2a due to the length relationship of the three sides of the right triangle. Accordingly, the diagonal length x inside the rectangular secondary planar coil portion 2a is the same as the shortest distance y1 between the opposing inner sides of the rectangular planar coil portion 2a, and the inner diameter y2 of the circular planar coil portion 2b. Longer. That is, in the rectangular secondary side planar coil portion 2a, there are more areas where the gap between the alignment magnet 4 and the secondary side coil 2a can be made larger than in the circular secondary side planar coil portion 2b. That is, the relationship is y1 = y2, x> y1, x> y2.

  And in order to suppress the influence of the alignment magnet 4 provided in the primary side non-contact charging module or the secondary side non-contact charging module, it is necessary that x ≧ m, preferably y1 ≧ m, in the rectangular coil.

  That is, the hollow portion inside the rectangular planar coil portion 2a is larger than the size of the alignment magnet 4, and there is no region where the hollow portion inside the rectangular planar coil portion 2a and the alignment magnet 4 overlap. In this way, even if the alignment magnet 4 is not circular but rectangular, the effect can be exhibited by adopting this embodiment.

When the space between the secondary planar coil portion 2a or 2b and the alignment magnet 4 is increased (the gap formed between the inside of the planar coil portion and the outer edge of the alignment magnet is increased), the alignment magnet 4 Since the influence is reduced, the L value reduction rate of the planar coil portion 2a or 2b can be reduced. When the planar coil part is rectangular, when the diagonal dimension x inside the planar coil part 2a is the same value as the inner diameter dimension y2 of the circular planar coil part 2b, the L value reduction rate of the rectangular planar coil part 2a is a circular plane. It becomes substantially the same value as the coil part 2b.

  This will be described with reference to FIG. As shown in FIG. 4, when the rectangular coil diagonal dimension of the rectangular planar coil portion 2a and the round coil inner diameter of the circular planar coil portion 2b are the same, the L value reduction rate of both planar coil portions is substantially the same value. Thus, the power transmission capability of the non-contact charging module is equivalent.

  Therefore, when the rectangular secondary planar coil portion 2a or the circular secondary planar coil portion 2b having the same number of turns in FIG. 7 is installed on the magnetic sheet 3 of the same size, as described above. Since the shortest distance y1 between the opposing inner sides of the rectangular secondary planar coil portion 2a and the inner diameter y2 of the circular planar coil portion 2b can be made the same size, y1 = y2 ≧ m can be satisfied.

  Then, x> y1 ≧ m is satisfied, and even if the planar coil portion 2a of the rectangular shape occupies the same space as the planar coil portion 2b of the round shape, the L value reduction rate becomes small, and the rectangular planar surface The power transmission capability of the non-contact charging module using the coil portion 2a can be improved.

  According to the standard, the diameter of the alignment magnet 4 is specified to be 15.5 mm or less, but the diagonal coil diagonal size of the rectangular planar coil portion 2a and the round coil inner diameter of the circular planar coil portion 2b are diagonally larger than 15.5 mm. As the size or inner diameter increases, the L value reduction rate decreases considerably. That is, it shows that it is less affected by the alignment magnet 4.

  On the other hand, if the diameter of the alignment magnet 4 is 15.5 mm or less, if the dimension of each planar coil does not change, there is a relative gap between the inner side of the planar coil portion and the outer edge of the alignment magnet. Since it is further increased, the L value reduction rate is further reduced and is less susceptible to the effect of the alignment magnet 4. Therefore, the power transmission capability of the non-contact charging module is improved. Alternatively, it is possible to reduce the size of the planar coil portion while maintaining the power transmission capability of the non-contact charging module.

  Therefore, when the space for storing the primary-side non-contact charging module of the non-contact charger is square and the space is limited, the magnetic coil 3 is square and the secondary planar coil portion 2a. Is preferably formed in a rectangular shape. As a result, compared to the circular coil, the rectangular secondary planar coil portion 2 a can be moved away from the alignment magnet 4, and the rectangular secondary planar coil portion 2 a is affected by the alignment magnet 4. It is hard to receive. Further, in the rectangular secondary planar coil portion 2a, the magnetic flux concentrates on the corner portion. However, since the distance between the corner portion and the alignment magnet 4 can be ensured, the influence of the alignment magnet 4 can be reduced.

That is, when the secondary planar coil is wound in a circular shape, the entire secondary planar coil 2b exhibits substantially the same magnetic field strength. However, when the secondary planar coil is wound in a substantially rectangular shape, the magnetic field concentrates at the corner. Therefore, the diagonal dimension x inside the rectangular planar coil portion 2a is positioned outside the outer diameter of the alignment magnet 4 (x ≧ m), so that the power can be transmitted while suppressing the influence of the alignment magnet 4. it can. Further, since the shortest distance y1 between the inner sides facing each other of the rectangular planar coil portion 2a is positioned outside the outer diameter of the alignment magnet 4 (y1 ≧ m), the entire rectangular planar coil portion 2a is aligned. It is located outside the outer diameter of the magnet 4, and the corner (corner) of the rectangular planar coil portion 2 a is located at a certain distance from the alignment magnet 4. Therefore, it is possible to further reduce the influence of the positioning magnet 4 on the rectangular planar coil portion 2a.

  In addition, when the planar coil portion is configured as described above, the size of the planar coil can be used regardless of whether the non-contact charging module is used with the alignment magnet 4 attached or used without the alignment magnet 4. It is possible to use the power transmission as it is without changing the power transmission capability. That is, irrespective of the presence or absence of the alignment magnet 4, the non-contact charging module provided with the planar coil portion can be used as it is in the size.

  In the present embodiment, the diagonal dimension (x) of the rectangular planar coil portion 2a is set to approximately 23 mm and the diameter (m) of the alignment magnet 4 is set to 15.5 mmΦ so as to satisfy the above-described relationship. The alignment magnet 4 is generally configured to have a maximum diameter of 15.5 mm and smaller. In view of downsizing and positioning accuracy, the positioning magnet 4 has a diameter of about 10 mm to 15.5 mm and a thickness of about 1.5 to 2 mm, so that positioning can be performed in a balanced manner. Because it can. Further, a neodymium magnet is used, and the strength may be about 75 mT to 150 mT. In the present embodiment, since the interval between the coil of the primary side non-contact charging module and the coil of the secondary side non-contact charging module is about 2 to 5 mm, it is possible to sufficiently align with such a magnet. . Therefore, if the secondary planar coil portion is wound in a circular shape, the diameter of the hollow portion is 15.5 mm or more, and if it is wound in a rectangular shape, the diagonal of the hollow portion is 15.5 mm or more, preferably the hollow portion. By making the side width of 15.5 mm or more, basically, the influence of the magnet can be reduced regardless of the size of the alignment magnet 4 provided on the other side.

  Further, FIG. 4 shows the L value reduction rate of the coil when the diameter of the alignment magnet 4 is set to 15.5 mmφ, so that the inner diameter of the circular coil and the side width of the hollow portion of the rectangular coil are 15.5 mm. (The coil size of both can be regarded as the same), the circular coil has an L value reduction rate of about 70%, while the rectangular coil has a diagonal distance of about 22 mm and its L value. The reduction rate is approximately 50%.

  Note that the diagonal dimension data of the rectangular coil (also referred to as a square coil) in FIG. 4 is a minimum of about 19 mm. When the diagonal dimension is 19 mm, the distance between opposing sides of the hollow portion inside the rectangular coil is about 13.5 mm. Therefore, in FIG. 4, when the diagonal dimension of the rectangular coil is 19 mm, the alignment magnet having a diameter of 15.5 mm and the hollow portion inside the rectangular coil are somewhat covered. That is, when the hollow portion inside the rectangular planar coil portion 2a is larger than the size of the alignment magnet, the L value reduction rate can be reduced.

  As described above, the rectangular coil is less susceptible to magnets than the circular coil. However, if both the primary side coil and the secondary side coil are rectangular coils, each other during the alignment at the time of charging. The corners must be aligned. Therefore, since it is difficult to align the angles during alignment, it is preferable that one is a circular coil and the other is a rectangular coil. That is, the angle adjustment is not necessary, and the rectangular coil can further suppress the influence of the magnet. Note that either the primary-side non-contact charging module or the secondary-side non-contact charging module may include a rectangular coil, and any of them may include a circular coil. However, the circular coil has a shape of a coil that is a partner of power transmission. However, since efficient power transmission is possible, it is preferable to provide a circular coil in the primary side non-contact charging module.

  In addition, compared with a circular coil, a rectangular coil is a coil whose corner R (the radius of the curve at the four corners) is 30% or less of the side width of the hollow portion (y1 in FIG. 7A). Say. That is, in FIG. 7A, the substantially rectangular hollow portion has curved corners. The strength of the conducting wire at the four corners can be improved by being slightly curved rather than perpendicular. However, if R becomes too large, there is almost no change from the circular coil, and the effect unique to the rectangular coil cannot be obtained. As a result of the study, it was found that when the side width y1 of the hollow portion is 20 mm, for example, if the radius R of the curve at each corner is 6 mm or less, the influence of the magnet can be more effectively suppressed. Further, considering the strength of the four corners as described above, the effect of the most rectangular coil described above can be obtained when the radius R of the curve at each corner is 5 to 30% of the side width of the substantially rectangular hollow portion. it can.

  As described above, in the present invention, the non-contact charging module is characterized in that the hollow portion inside the planar coil portion is larger than the size of the magnet. At this time, when the hollow part inside the planar coil part is larger than the size of the magnet, when the transmitting side non-contact charging module and the receiving side non-contact charging module are aligned, for example, the transmitting side non-contact charging module ( It means that the magnet provided in the other non-contact charging module does not overlap the hollow part of the planar coil part of the receiving-side non-contact charging module. That is, when the transmission-side contactless charging module and the reception-side contactless charging module are viewed from above, the magnet provided in the transmission-side contactless charging module does not protrude from the hollow portion of the reception-side contactless charging module to the coil surface. It means to fit in the hollow part.

  According to the non-contact charging module and the non-contact charging apparatus using the same according to the present invention, the non-contact module can be downsized even if there is a positioning magnet. It is useful as a non-contact charging module for various electronic devices such as terminals and mobile devices such as video cameras.

DESCRIPTION OF SYMBOLS 1 Non-contact charge module 2 Plane coil part 2a Plane coil part (rectangle)
2b Planar coil (circular)
21 Coil 3 Magnetic sheet 31 Flat part 32 Convex part 33 Concave part 4 Magnet

Claims (3)

A non-contact charging module that transmits power by electromagnetic induction with the other non-contact charging module,
When aligning with the other non-contact charging module, the circular magnet provided in the hollow portion of the planar coil portion of the other non-contact charging module is used for alignment, and the circular magnet is not used. In a non-contact charging module that does not have a positioning magnet,
A planar coil portion in which a conducting wire is wound with a substantially rectangular hollow portion inside, and
A substantially rectangular magnetic sheet for mounting the coil surface of the planar coil portion,
The magnetic sheet rather larger than the planar coil portion,
The non-contact charging module , wherein a length of a shortest distance between opposing inner sides in a hollow portion having a substantially rectangular shape of the planar coil portion is longer than a diameter of the circular magnet . A charger comprising the contactless charging module according to claim 1 as a charging contactless charging module. An electronic apparatus comprising the non-contact charging module according to claim 1 as a power-receiving non-contact charging module.